Extra Blank Page

In a letter, I have two bar codes on the bottom. The bar codes print
correctly as well as the rest of the letter. However, a blank page also
comes out behind each letter.
The entire letter consists of Advanced Text and Variables. The barcodes
are Barcode39.
There is more than enough space between the bottom of the bar codes and
the edge of the paper.
Does anyone have any idea why a blank page is output?
Thanks...
Sincerely,
bob picorelli
IT Applications
22nd floor
Phone: 347 643-3078
email@removed